Gear-cutting machine



Qd, 22, 1929, A.- H. CANDEE ET AL GEAR CUTTING MACHINE Filed D60. 3l. 1926 3 Sheets-Sheet Jillan Ii Candee BYJgmLsIcbhazzsozz ATT Oct. 22, 1929. A. H. cANDEE l-:T m.v 1,732,633

GEAR CUTTING MACHINE Filed Dec. 51. 1926 s sheets-sheet 2 INVENTOR Ellzml Cazzd Wam ATTOR Oct. 22, 1929. A.. H. CANDEE ET AL 1,732,633

GEAR CUTTING MACHINE Filed Dec. 51.1 19426 3 Sheets-Sheet 5 INVENToR lllian IL cazzdee is imparted between the tool and the blank.

`The present invention Will be described in connection with a machine for generating bevel gears. It is to be understood, however, that this invention is applicable to the production of other types of gears also, Whether generated or non-generated.

In the machine illustrated, the tool is indicated at T. This tool T is mounted upon a tool head 10` which is adjustably secured to the tool slide 11 which is adapted to be reciprocated in guide ways 12 formed in an arm 13 which is pivotally adjustable upon the cradle 14. The ,cradle 14 is rotatably mounted in bearings 15 and 15 formed in the frame 16 of the machine.

The blank to be cut is secured to a blank spindle 18 which is journaled in a blank support 1S). The blank support 19 is adjustable, as will be more particularly 'described hereinafter, upon the bed or frame 1G so as to permit adjusting thel blank to be cut into the proper cutting relation with reference to the tool. 'i

During the operation vof the machine illustrated, a reciprocating motion is imparted tothe tool, a'continuous rotary motion at a uniform velocity is imparted te the blank spindle, and `simultaneously a slow rotary movement is imparted lto the cradle.

7 The reciprocating movement of the tool is produced by rotation of the crank 2O which is provided with a spindle 21 which is journaled in a 'suitable bearing 22 formed in the cradle 14. VThe crank 2O is operatively connected with the'tool slide 11 vby means of the connecting rod 23, one end of which is connected with the toolslide 11 by means of the pin 24e-and the other end of which is connectedwith the crank plate by means of the slidably adjustable block 25.

' The rotary motion of the crank will impart a motion at a'variable velocity of a harmonic nature to the tool. This motion combined with the continuous rotary indexing motion of the blank will produce, as already stated, an C3-shaped tooth. We retain the advantages of the crank drive and avoid this form of tooth by driving the tool crank at a varia- A ble velocit-y.

The crank is driven from the motor 28 which is mountedupon a suitable bracket secured to the frame of the machine and which drives through a pair of speed change gears 29 and 30, a stub shaft 31, a bevel pinion 32, and a bevel gear 33, the main drive shaft 34. This main drive sha-ft 34 is journaled in suitable bearings coaXially ofthe cradle 14. Mounted on the drive shaft 34 and connected through a splined connection therewith,`is along-faced helical pinion 35. This pinion' 35 meshes withahelical gear 36, which is keyed to the shaft 37 ,and transmits to the shaft 37, through the gear 36, the rotary motion Of the main drive Shaft 34.

The helical pinion is provided with a head 38 through which it is rotatably connected with a sleeve 39 which is adapted to be reciprocated at a variable velocity along the drive shaft 34. The sleeve 39 reciprocatcs in grooves formed in a guide member 40 which is secured to the cradle (Figures 2 and 4),. 1

Any suitable means may be employed for imparting to the sleeve 39 its reciprocating movement, but for this purpose, we, preferably employ a crank 41 which is connected by means of the crank pin 42 with the slidable sleeve 39.

The crank imparts to the sleeve 39 and pinion 35 a reciprocatory motion at a variable velocity of a harmonic nature. Due to the helical nature of the gears and 3G, this variable velocity reciprocating motion is combined with the rotational motion of the shaft 34 and transn'iitted to the shaft 3l' as a rotary motion at a variable velocity. The shaft 37 carries a spur pinion 45 which meshes with a spur gear 46 which is secured to the crank plate 20. Through the gearing just described, therefore, the crank is driven centinuously at a variable velocity and the tool receives, therefore, a motion which is a combination of two variable velocity motions. lVhen a tool so dr' ven is reciprocated across the face of a continuously rotating blank, if the dimensions of the determining elements are properly chosen, it will cut a groove in the blank which extends substantially in one direction and the tool clearance angle will be substantially constant throughout the length of the cut.

The crank 41 may be driven in any suitable way. As shown, the crank spindle 48 is journaled in a suitable bearing in the cradle 14 and has secured to it intermediate its length a bevel gear 49 which meshes with and is driven by a bevel pinion 50 which is secured to the shaft 37. The gear reduction 50-49 is preferably so proportioned to the reductions 35, 36, 45, 46, that the crank 41 rotates at twice the speed of the tool crank 2O as this has Vbeen found to give the best results as regard the tooth curve to be produced.

The machine illustrated is particularly adapted for the cutting of bevel gears. In bevel gear pairs, the pinion is usually much smaller than the gear. To hold the dill'erent blanks rigidly du ring cutting different mountings are ordinarily required for gear and pinion blanks. This usually means that dillicrent machines must be employed in cutting gears and pinions. The duplication of machines is avoided with the machine shown by providing means at either end of the blank spindle for securing to one end a gear blank and to the other end a pinion blank and by providing a support for the blank spindle which may be swivelled end for end to bring either end of the blank spindle and the blank carried thereby into operative relation with the tool. The blank spindle 1S, as has al.- ready been described, is journaled in a support 19. Une end et the blank spindle is constructed so that a gear blank G shown in .section in Figure 1 may be secure-:l thereto and the other end ol the blank spindle is so foi-ined that a pinion blank l), shown in dotted lines in Figure 1, niay be mounted thereon. For this purpose.. the blank spindle is provided adj cent one end with a head or shoulder 5o to which is secured the tace plate 5G. it its opposite end. the blank. spindle is provided with an end 'face oit sutlicient diameter to 'forni a Fl' against which the pinion blank l? inay be lirinly clamped.

The face plate 56 serves to sup-port a gear blank7 when the machine is to be used in cnttinrij large sized gears, the blank G being secured to the face plate by means ol the spacing; disc 58, the olainps 59, and the bolts 6() which are provided with T-heads Which engage in corresponding radial slots (i1 'formed in the tace plate. The disc 58 is brought into clamping engagement with the gear G by n'ieans ot the tapered clamping ineinber 62 which is adapted to be securely seated in a tapered bore in the blank spindl. 18 by ineans of a threaded rod G8. The rod 63 is provided adjacent its outer end with a head 64e which .is adapted to en the enter end face et the blank spindle. The bolts and the clamps together with the disc 58 and rod 63 serve to securely clanip the `gear blank G upon the blank spindle for rotation therewith.

The seat 57 formed by the enter end face oil the blank spindle provides a snioient supn port for a pinion blank and .it a pinion blank P is to be ont, it can be clamped against this J. SiGt `seat by means of the rod 63 and clampingplate G4 or by nieans of a siinilar rod ot suitable len gt-h.

The support 19 b as 'formed integral With it, adj acentthepinion en d of the blank spindle, a bracket 65 which may serve as a support for a steady-rest for the pinion blank, so that the pinion blank may be held very rigidly duringthe cut-ting.

The support 19, as has already been previously s ated. is rotatably adjustable on the :traine so that either end ot the blank spindle may be brought into operative engaajeinent vl ith. the tool. :lo that eitl'ier a pinion blank or x ar blank n' be rut ir in tbe machine., amb the support 19 is formed with an annular bearing 67 which sf. ts on an annular projection GS formed on a sli e 69. 'lhe support 19 swivels about an alle coaxial with the bearing; 67. The sivivelling adjustment of the support 19 is accomplished by rotation of theshatt 70, by means et a Wrench, this shaft T0 carrying,l a spur pinion 71 which meshes with a spur gear 72 Which is secured to the slide 69 and Which is mounted coa-itially of' the bearing G7. Rotation of the shaft 70 nieves the support 1 9 about its axis to bring either end, as may be desired, et' 'the blank spindle into operative relation with reference to the tool. The slide 69, upon Which the blank support 19 is swivelled, is in turn mounted upon a bed plate To which in turn is mounted on the traine 16 of the inachine. The slide 69 is slidably adjustable upon the plate tor the purpose et movingthe bl; i to be cnt toward and array from the axis of. the cradle 13 so as to locate the ape): et the blank in the desired relation to the .ai-iis of the cradle. 1n cutting bevel lgears. 'the sli de G9 Will, preferably, be so adjusted that the arie. ot the cradle passes through the apex of the blank, so that when the machine is in operation a rolling; motion Will. be iinparted. between the tool and blank corresponding to the niesh between a `graaf..- and crown gear, Where the axis of the cradle represents' the axis et the crown gear.

The lateral adjustment ot the slide (il) is er'lected by rota n el the shalft 7"? and the pinion 78 carried thereby which meshes With a rack T9 which is secured to the plate 75. 'llbe slide lil) can be secured in any adjusted 't on by means ot bolts 8O which engage 'l"-slots 81 termed in the plate 75.

The `plate l5 ananlarly adjustable about erseets at right angles the an anis which int Y airis ot' the cradle, so that 'tle blank can be adjuffsted into the proifer ci ng pla. o. For the purpose oit' this atljustn'ient, the plate l is provided with an extension or arin 83 which has lrearingv upon a stud @el secnred to the bed 16 the machine. `This adjustment may be elle 'ed by rotation of the pinion Elli which ine-elias with a segment 8G secured the bed 1 j W' .snail nest .describe the ineans 'for iinparting; to the blank its continuons rotary indexing' movement. Sefnret to the inten drive shaft 311; (Figure El) intermediate its lcnej'h is a bevel ear 90 which meshes with and drives a bevo naar 91 which, is fastened to a diagonal shaft (Figures 1 and 2) which is jonrnalrd in stumble bearinojs in the 'traine or a bracket secure` thereto. The shalt 92 carries a bevel gear 953 Which n'ieslies with and drives a bevel gmx.' 9d upon a. .shaft 95. This shalt 95 drives the shalt Q6 through the differential .sie s 97. rllie shaft 9G drives a telescopiiw1 sha1.. 98 through the bevel tqcar 99, the 'bevel oear 100, the sleeve 101 to which this bevel is secured, the bevel gear 1.02, also secured to this sleeve7 and the bevel Lgear 103.

The 'telescoping shalt 98 carries a bevel gear 1011 which meshes with and drives a bevel gear 105 which is secured to an npright shalt` 105 that is journaled in the support 19 coafrially of the swivel?inav axis of this support. rlhe telescopingshatt 955 permits of adjustment of the support 19 about its axis, While the mounting of the bevel gear and' shaft 106 coaXially of the swivelling aXis of this support 19 permits of continuously driving the shaft 106 regardless of the swivelling adjustment of the support 19, so that motion is transmitted to the shaft 106 in any position of the support 19.

Secured to the shaft 106 is a bevel gear 107 which meshes with a bevel gear 108 upon a stub shaft 109 which is jcurnaled in suitable bearings in the support 19 and Which carries a miter gear 110 that meshes with a miter gear-111 upon a transverse shaft journaled in the bracket 19 which drives through the yindexv change gears 112, 11.3, 114 and 115 the .worm shaft 116.

The worm shaft 116 carries a worm 11'? which meshes with a worm Wheel 118 which vis secured to the face plate 56. Through the gearing described, a continuous rotary motion is imparted froml the main drive shaft 34 to theblank spindle to rotate the blank continuously on its axis. The worm shaft 116 and the shafts carrying the change gears 112, 113 and 114 are all journaled in the blank Vsupport 19 and all moved about the axis of the shaft 106 in t-heswivelling adjustment of the support 19.

For the purpose of generating the tooth proles, Where generated gears are to be produced, ,a continuous rotaryl motion is imparted to the cradle 14. This motion is derived from the-shaft92 (Figures 1 and 2) through the bevel gears 93 and 94 and the shaft 95. `rlhe shaft 95 drives a parallel shaft 120 (Figure 2) through the feed change gears 121, 122, 123 and 124, the last being secured to the shaft 120. The shaft 120 carries adjacent its inner end a bevel gear 125 which able thereon to engage, through the ratchet teeth with which it is provided at each end, with one or other of the bevel gears 126 and 127. The whole forms a usual type of reversing mechanism, provided in the present ma.- chine for the purpose of controlling the direction of rotation of the cradle. The yoke 129 can be moved into engagement with either of the gears 126 or 127 by means of the lever arm 130 (Figure 1) which is pivotally mounted on the frame of the machine.

The transverse shaft 128 carries at its farther end a worm 131 which meshes with and drives a worm wheel 132 secured to the shaft 133 which is journaled in the frame. The shaft 133 carries adjacent one end a worm 134 (Figures 2 and 3) which meshes with a worm wheel 135 which is keyed to an upright shaft 136 which is suitably journaled in the frame.

The upright shaft 136 carries a worm 137 which meshes with a worm wheel 138 which is secured to the cradle 14. By the means described, a slow rotary motion at a uniform velocity is imparted to the cradle to move the, cradle on its axis. The machine illustrated is s0 constructed that the axis of the cradle intersects the of the blank in its apex, when the tool and blank are in proper cut-- ting position. 1n the machine illustrated, the tool and blank are rolled relatively to each other in a manner corresponding to the rolling motion of a gear and a basic crown gear.

The tool reciprocation and the blank rotation must be so timed relatively to each other that the tool on each succeeding stroke cuts in a new tooth space of the blank. Now the main drive shaft 34 is journaled'coaxially of the cradle 14 and it derives its motion directly from the motor and is not affected by movement of the cradle. Because of the slow rotational movement of the cradle, the timed relation between the tool and blank will be disturbed. Some means must be en'iployed, therefore, to compensate for the cradle movement. This might be done by using especially calculated ratios for the change gears, but this would require new calculations whenever the rate of roll is changed and it would also be necessary to carefully reset the tool when starting a new cut. A differential. is, therefore, preferably, employed for the purpose as it alufays maintains the proper relation between the tool, blank and cradle movements independently of the rate and direction of the generating roll.

In the machine illustrated, the differential is incorporated in the blank drive. This differential comprises the differential gears 97 (Figure 1) already mentioned and the housing` 140 for these gears.

The compensating motion is ell'eeted by rotation of the housing 140. The housing 140 is rotated from the shaft 133 by means at the bevel gears 141 and 142, the transverse shaft 143 (Figure 2), the bevel gears 11i and 145, the shaft 146, the ratio change gears 147, 148,149, and (Figures 1 and 2) the shaft 151, the spur pinion 152, and the spur gear 153, the latter being secured to the differential housing 140.

By the gearing just described, an additional motion is imparted to the sha ft 96, and thence to the blank spindle to compensate for the movement of the cradle thus maintaining the correct timed relation between the tool and blank movements.

lith the single differential the ratio `Change gears 147, 148, 149 and 150 have to be different for cutting gears and pinions of opposite hand of spiral. If it is desired to cut gears of opposite hand. on this machine Without recalculating and changing the ratio change gears, a second differential may be incorporated in the blank spindle drive according to the principles set out in our copending application No.. 158,083, filed December 30, 1926.

The adjustments required for positioning the blank in the correct cutting relation with reference to the tool have already been described. rlhe tool adjustments and the mechanism for clapping the tool are substantially the saine as those described in our. prior Patent No. 1,616,439 already mentioned and they need only be briefly mentioned here as reference can be had to that application for a more detailed description thereof.

The tool T is mounted in a suitable holder which is secured to aclapper block 155 which is pivotally mounted upon a carrier 156. The carrier 156 is provided with an arcuate lower surface which is adjustable upon a corre spending curved seat 157 formed on the tool head 10. The adjustment of the clapper block support 156 on the head 16 permits of positioning the tool so as to cut With the proper clearance angle Without in any Way affecting the pressure or spiral angles of the gea-rs to be produced,

The head is slidably adjustable upon the tool slide 11,. so that the tool can be adjusted toward and from the center of the machine, that is the center of the cradle, for cutting gears of dill'erent cone distances. This adjiistnient can be elected by means such as described in our prior application mentioned. The head 10i can be secu-red in any adjusted position` by means of the bolts 158 which engage in Tslots 159 formed in the slide 11.

The tool slide 11 reciprocates under actuation of the crank E and connecting rod Q3 in the guide Ways 12 formed in the arm 13. This arm 13 is, preferably, pivotally mounted upon the cradle for adjustment about an airis X, Figure 3, which is` oii'set from the axis Y of the cradle. By making this arm adjustable about an oifset axis, the tool path can be inclined or offset with .reference to the axis of the cradle and the apex of the blank, thereby affording aV complete control over the l spiral anole to be produced upon the gears to be cut as more particularly described in the copending application referred to. For the purpose of effecting this adjustment the arm 13 carries a gear (not shown)I which meshes with the segment 160 (Figures 2 and 3) which is securedto the cradle. The clapping movement ofthe tool, effected by movement of the clapper block 155 about its pivot 161, is controlled from the cam 162V which is formed integral with the crank plate 26 (Figure 2)` and is accomplished.

through rotation. of this cam, movement of the rod 163 Which carries a roller 164 which engages in the camv groove, and movement of I the telescoping shaft 165, all operating substantially as described in our Patent No. 1,616,439 already mentioned.

The tool, as usual, cuts on its stroke in one direction and is out of cut-ting position on the return stroke. The movement of the blank at a uniform` velocity combines with `the planing movement of the tool to produce the toot-h curve during the cutting operation and acts to index the blank during the period the tool is out of cutting position and is being returned for opera-tion upon a neu tooth space.

The machine shown is a single tool machine, but, it Will be understood, that by a suitable arrangement tivo tools may be also employed.

Thile We have described our invention par ticularly With refe-rence to a machine for `generating bevel gears, it is to be understood that this invention is applicable also to the pro duc-tion of other types of gears, as spur, helical, herringbone, and hypoid, whether gen-V erated or non-generated- In the cutting of spur, helical, and herringbone gears, the tool Will be rec-ip-rocated in a plane parallel to the blank axis according to the principles set forth in our copending application No. 145,-` 903, November 2, 1926. In the `cutting of hypoid gears, the blank axis will preferably be oifset relative to the axis of the cradle.`

ln general, itl may be said, that While We have described our invention in connection with a specific structure and in connection with specific uses for said structure it is to be understood that the invention is capable of various further modifications and uses and that the structure may be modified Within the limits of the invention Without depart ing from its intent or the scope of the tot lowing claims and that this application is intended to cover any adaptations, uses, or

tinuously on its axis at a uniform velocity,

means adapted to drive the tool at a variable velocity across the faceof the blank and means actuating said driving means at a variable velocity, whereby the tool receives a motion Which is a combination of two variable movements and which combines with the blank rotation to produce the longitudinal tooth shape.

2. In a machine for producing` gears, a

blank.,` support, a b-lankxspindle journaled therein, a tool support, a tool mounted thereon, means for rotating the blank spindle continuouslyV on its airis` at a uniform velocity, means adaptedto drive the tool across the face of the blank aty a variable velocity of a harmonic nature,` means for actuating said 'driving means, including a train of gearing one element of which is driven at a variable velocity of a harmonic nature and at a multiple the speed imparted to the tool driving means by said'train, whereby the tool receives amotion which'is-a combination oftwo variable movements an-d which combines with the blank'rotationto produce the longitudinal tooth shape,

^ 3.`In` a machine for producing gears, blank support, a blank spindle j ournaled therein, a tool support, a tool mounted thereon,"means for rotating` thev blank spindle continuously on itsjaxis at a uniform velocity, means adapted to drive the tool at a variable velocityV across the face of the blank, means for actuating said driving means at a variable velocity, whereby the tool receives a motion which is a-combination of two variable movements andV which combines with the blank rotation to produce the longitudinal tooth shape, and means for simultaneously producing a relative rolling motion between the tool and blank to generate the tooth profiles.

4. In a Vmachine for producing gears, a blank support, a blank spindle journaled thereon, a tool support, a tool mounted thereon', means forr rotating the blank spindle continuously on its axis at a. uniform velocity, means adapted to drive the tool across the face ofthe blank at a variable velocity of a harmonic nature, means for actuating said driving means including a train of gearing one element of which is driven at a variable velocityof a harmonie nature and at a multiple the speed imparted to the tool driving i means by said train, whereby the tool receives a motion which is a combination of two variable movements and which combines with the blank rotation to produce ythe longitudinal tooth shape, and means for simulta neouslyv producing arelative rolling motion between the tool and blank to generate the tooth profiles.

5. In a Vmachine for producing gears, a

' blank support, a blank spindle journaled thereon, a tool support, a tool mounted there- "on, Yac'radle upon which one of said supports is.l mounted, means for rotating the blank spindle continuously on its axis at a uniform Y velocity, means adapted to drive the tool at a blank rotation to'produce. the longitudinal tooth shape, and means for in'iparting to the cradle a rotary motion on its axis.

6. In a machine for producing gears, a blank support, a blank spindle j ournaled therein, a tool support, a tool mounted thereon, a cradle upon which one of said supports is mounted, means for rotating the blank spindle continuously on its axis at a uniform velocity, means adapted to drive the tool across the face of the blank at a variable velocity of a harmonic nature, means for actuating said driving means including a train of gearing, one element of which is driven at a variable velocity of a harmonic nature an d at a multiple the speed imparted to the tool driving means by said train, whereby the tool receives a motion which is a combination of two variable movements and which combines with the blank rotation to produce the longitudinal tooth shape, and means for imparting to the cradle, a rotary motion on its axis.

7. In a machine forl producing gears, a blank support, a blank spindle ournaled therein, a tool support, a tool mounted thereon, means for rotating the blank spindle con- .inuously on its axis at a uniform velocity, a crank for reciprocating the tool across the face of the blank and means for rotating` said crank at a variable velocity.

8. In a machine for producing gears, a blank support, a blank spindle journaled therein, a tool support, a tool mounted thereon, means for rotating the blank spindle continuously on its axis at a uniform velocity, a crank for reciprocating the tool across the face of the blank, and means for driving the crank at a variable velocity of a harmonic nature, including a train of gearing, one clement of which imparts to the train a variable velocity movement and which is driven at twice the speed of the crank.

9. In a machine for producing gears, a blank support, a blank spindle journaled thereon, a tool support, a tool mounted thereon, means for rotating the blank spindle continuously on its axis at a uniform velocity, a crank for reciprocating the tool across the face of the blank, means for rotating the crank at a variable velocity, and means for simultaneously imparting a continuous relative rolling movement between tool and blank to generate the tooth profiles.

10. In a machine for producing gears, a blank support, a blank spindle journaled therein, a tool support, a tool mounted thereon, means for rotating the blank spindle continuously on its axis at a uniform velocity, a crank for reciprocating the tool across the face of the blank and means for driving said crank at a variable velocity of a harmonic nature including a train of gearing, one element of which imparts to the train a variable velocity motion and which is driven at a multiple the speed of the crank, and means for simultaneously producing a continuous relative rolling movement betiveen the tool and blank to generate the tooth proliles.

11. ln a machine for producing gears` a blank support, a blank spindle journaled therein, a tool support, a. tool mounted thereon, a cradle upon which one oll said supports is mounted, means for rotating the blank spindle continuously onits airis at a uniform velocity, a crank for reciprocating the tool across the face oiIl the blank, means `itor rotating said crank at a variable velocity, and `n'ieans for simultaneously imparting a continuous rotary movement to the cradle on it-s axis.

12. n a machine tor producing gears, a blank support, a blank spindle journaled therein, a tool support, a tool mounted there on, cradle upon Which one of said supports is mounted, means for rotating the blank spindle `continuously on its axis at a uniform velocity, a crank `for reciprocating the tool across the face of the blank, means tor driving said crank at a variable velocity including a train oll gearing, one element of which imparts to the train a variable velocity movement oi a harmonic nature, and which is driven at twice the speed of the crank, and means for simultaneously imparting to the cradle a continuous movement on its anis.

13. ln a machine for producing gears, a blank support, a blank spindle journaled therein, a tool support, a tool mounted thereon, means for rotating the blank spindle continuously on its axis at a uniform velocity, a crank for reciprocating the tool across the face of the blank, means for driving the crank continuously7 at a variable velocit-y, including a train ol gearing one element of Which is driven by a second crank and means for driving the second crank at a multiple the speed of the tool crank.

1li, In a machine for producing' gears, a blank support, a blank spindle journaled therein, a tool support, a tool mounted thereon, means for rotating the blank spindle continuously on its a Yis at a nniiorm velocity, a crank for reciprocating` the tool across the tace of the blank, means for driving the crank continuously at a variable velocity including a train of gearing, one element ot' which is driven by a second cranlnand means for rotating the second crank tivice for each complete revolution of" the tool crank.

15.111 a machine for producinggears, a blank support, a blank spindle journaled thereon, a tool support, a tool mounted there on, means for rotating the blank spindle continuously on its axis at a uniform velocity, a crank for reciprocating' the tool across the :tace of the blank, means for driving the crank continuously at a. variable velocity including' a train of gearing, one element of which is driven by a second crank, means for driving the second crank at multiple of the speed of the tool crank, and means for simultaneously producing a relative rolling motion between the tool and blank to generate the tooth profiles.

16. In a machine for producing gears, a blank support, a blank spindle journaled therein, a tool support, a tool mounted thereon, a cradle upon which one ot said supports is mounted, means for rotating the blank spindle continuously on its axis at a junil'orm velocity, a crank for reciprocating the tool across the tace of the blank, means ttor driving the crank continuously at a variable velocity including a train ot gearing one elementof which is driven by a second crank, and means for driving' said second crank at a multiple the speed of the tool crank rotation, and means for simultaneously imparting to said cradle a continuous rotary movement on its axis.

17. In a machine lor producing gears, a blank support, a blank spindle journalei; therein, a tool support, a tool mounted thereon, means tor rotating the blank spindle continuously on its axis at a uniform velocity, a crank for reciprocating the tool across the tace of the blank, means for driving the crank including a pair ot helical gears, means for impart-ing a continuous rotary motion to said gears, and means for simultaneously reciprocating one of said gears axially at a variable velocity a plurality of times i'or each complete revolution of the tool crank.

18. In a machine lor producing gears, a blank support, a blank spindle journalcd therein, a tool support, a tool mounted thereon, means for rotating the blank continuously on its axis at a uniform velocity, a crank for reciprocating the tool, means 'lor driving the crank including a pair ot helical gears, means l'or imparting a continuous rotary motion to said gears, and means for simultaneously reciprocating one ot said gio-ars il 'ally at a variable velocity a plurality ot' times during each complete revolution of the crank, and means iior sin'iultanemisly producing a relative rolling motion between the tool and blank-to generato the tooth profiles.

19; In a machine 'or producingI a blank support, a blank s ai die journaled therein, a tool support, a tool mounted thereon, a cradle upon which one of said supports is mounted, means for rotating the blank spindle continuously on its axis at a uniform velocity, a crank for reciprocating the tool across the 'tace of the blank, means for driving the crank including a pair of helical gears, means tor imparting a continuous rotary motion to said gears and means for simultaneously reciprocating one ot said `gears axially at a variable velocity a plurality of times tor each complete revolution oit the tool crank, and means for simultaneously imparting to the cradle a continuous rotary movement on its axis.

20. Ina machine for producino' gears, a

blank support, a blank spindle journaled therein, a tool support, a tool mounted thereon, means for moving` the tool at a variable velocity across the face of the blank, means for rotating the blank spindle continuously on its axis at-a uniform velocity, and means for simultaneously imparting betiveen tool and blank an additional movement at a variable velocity, said means including a pair of helical gears, means' for rotating the gears continuously and means vfor simultaneously reciprocating one of said gears axially at a variable velocity.

2l. ln a machine for producing gears, a blank support, a blank spindle journaled thereon, a tool support, a tool mounted thereon, a carrier upon whichV one of said supports is mounted, means for moving the tool at a variable velocity across the fac-e of the blank, means for rotating the blank spindle continuously on its axis at a uniform velocity, means for imparting a continuous movement to said carrier, and means for simultaneously imparting between tool and blank an additional movement at a variable velocity, said means including a pair of helical gears, means for rotating said gears continuously, and means for simultaneously reciprocating one of said 0ears axially at a variable velocity.

. '22. In a machine for producing gears, a blank support, a blank spindle journaled therein, a toolsupport, a tool mounted thereon, a crank for recilnocatingthe tool at a variable velocity across the face of the blank,

y means for rotating the blank spindle continuously on its axis at a uniform velocity, and means for simultaneously imparting between the tool and blank an additional movement at a variable velocity, ysaid means including a pair of helical gears, means for continuously vrotating said gears, and means for reciprocating one of said gears axially at a variable velocity a plurality of times during each revolution of the crank.

In a machine for yproducing gears, a blank support, a blank,` spindle journaled therein, a tool support, a tool mounted thereon, a carrier upon which one of said supports is mounted, a crank for reciprocating the tool across the face of the blank, means for rotating the blank vspindle continuously on its axis at a uniform velocity, means for simultaneously imparting to said carrier a continuous movement, and means for simultaneously imparting between the tool and blank an additional movement at a variable velocity, said means including a pair of helical gears, means for rotating the gears continuously, and means for reciprocating one of said gears axially at a variable velocity a plurality of times during each revolution of the tool crank.

24:. ln a machine for producing gears, a blankv support, a blank spindle ournaled therein, a tool support, a tool mounted thereon, a crank for reciprocating the tool, means for rotating the blank spindle continuously on its axis at a uniform velocity, a cradle upon which one of said supports is mounted, 1.

means for imparting to said cradle a continuous rotary movement on its axis and means for simultaneously imparting between tool and blank an additional movement at a variable velocity, said means including a pair of helical gears, means for rotating the gears continuously, and means for reciprocating one of said gears axially ata variable velocity a plurality of times during each rotation of the tool crank.

25. In a machine for producing gears, a blank support, a blank spindle liourualed therein, a tool support, a tool mounted thereon, means for rotating the blank spindle continuously on its axis at a uniform velocity, a crank for reciprocating the tool across the face of the blank, means for driving the crank including` a pair of helical gears, means for imparting a continuous rotary motion at a uniform velocity to said gears, and means for simultaneously reciprocating one of said gears axially at a variable velocity.

Q6. The combination with a driven shaft, a driving shaft and means for driving the first shaft from the second, including a pair of helical gears, one of which is ixedly secured to said driven shaft and the other of Which is slidably mounted on the drive shaft but is held against rotation relative thereto, of means for rotating the driving shaftand means for simultaneously reciprocating said second gear, thereby to impart to said driven shaft a movement which is the resultant of the reciprocating and rotary motions of said second helical gear.

27. The combination with a driven shaft, a driving shaft, and means for driving the first shaft from the second including a pair of helical gears, one of which is ixedly secured to the driven shaft, and the other of which is slidably mounted on the driving shaft but is held against rotation relative thereto, of means for rotating the driving shaft continuously at a uniform velocity and means for simultaneously reciprocatingsaid second gear at a variable velocity, whereby to impart to said driven shaft a movement at a variable velocity Which is a resultant of the reciprocating and rotary motions of said second helical gear.

ALLAN H. CANDEE. MAGNUS H. JOHANSON. 

